Proteoliposome-based model for screening inhibitors targeting histidine kinase AgrC

Area of Science:

• Microbiology
• Biochemistry
• Pharmacology

Background:

• The AgrC protein is a key component of the Staphylococcus aureus agr quorum-sensing system, sensing environmental signals and initiating intracellular responses.
• AgrC's role as a signal transducer makes it a promising target for developing novel quorum-sensing inhibitors to combat bacterial infections.

Purpose of the Study:

• To construct and validate a proteoliposome-based model for screening AgrC inhibitors.
• To identify potential quorum-sensing inhibitors targeting AgrC from traditional Chinese medicine monomers.

Main Methods:

• Incorporation of AgrC into liposomes to create a proteoliposome model.
• Optimization of liposome dissolution for successful AgrC proteoliposome reconstruction, ensuring native-like membrane orientation and function.
• Screening of 14 traditional Chinese medicine monomers using the AgrC proteoliposome model.

Main Results:

• Rhein and aloeemodin were identified as AgrC inhibitors.
• These compounds exhibited dose-dependent inhibition of bacterial growth.
• Subinhibitory concentrations of rhein and aloeemodin significantly reduced the expression of agr-regulated virulence factors (hla, clfA, clpP).

Conclusions:

• Rhein and aloeemodin show potential for inhibiting the Staphylococcus aureus agr signaling pathway.
• The AgrC proteoliposome model is a feasible and effective platform for drug screening against quorum-sensing systems.